Buggy code:
@ Component public class SimpleHttpClient { private static final Logger logger = LoggerFactory . getLogger ( "SimpleHttpClient" ) ; private int connectionTimeout = 60000 ; private int readTimeout = 60000 ; private Integer slowTime ; private Map < String , String > commonHeaders = new HashMap < String , String > ( ) ; private SSLContext sslContext = null ; private HostnameVerifier hostNameVerifier = null ; private Proxy connectionProxy = Proxy . NO_PROXY ; public static String get ( String url ) { } public static String get ( String url , Map < String , String > headers ) { } public static String get ( String url , Map < String , String > headers , String charset ) { } public static String get ( String url , Map < String , String > headers , Integer readTimeout ) { } public static String get ( String url , Map < String , String > headers , String charset , Integer readTimeout ) { } public static String get ( String url , Map < String , String > headers , String charset , Integer conTimeout , Integer readTimeout ) { } public static String post ( String url , Map < String , Object > params ) { } public static String post ( String url , Map < String , String > headers , Map < String , Object > params ) { } public static String post ( String url , Map < String , String > headers , Map < String , Object > params , String charset ) { <START_BUG> return SimpleHttpClient . post ( url , headers , params , charset ) ; <END_BUG> } public static String post ( String url , Map < String , String > headers , Map < String , Object > params , Integer timeout ) { } public static String post ( String url , Map < String , String > headers , Map < String , Object > params , String charset , Integer timeout ) { } public static String post ( String url , String postStr ) { } public static String post ( String url , Map < String , String > headers , String postStr ) { } public static String post ( String url , Map < String , String > headers , String postStr , String charset ) { } public static String post ( String url , Map < String , String > headers , String postStr , Integer timeout ) { } public static String post ( String url , Map < String , String > headers , String postStr , Integer timeout , String charset ) { } public static String post ( String url , Map < String , String > headers , String postStr , Integer conTimeout , Integer readTimeout , String reqCharset , String resCharset ) { } private String doExecute ( String url , String method , Map < String , String > header , String body , Integer contimeout , Integer readtimeout , String reqCharset , String resCharset ) { } public HttpURLConnection prepareConnection ( URL url , String method , Map < String , String > headers , Integer contimeout , Integer readtimeout ) throws IOException { } public int getConnectionTimeout ( ) { } public void setConnectionTimeout ( int connectionTimeout ) { } public int getReadTimeout ( ) { } public void setReadTimeout ( int readTimeout ) { } public SSLContext getSslContext ( ) { } public void setSslContext ( SSLContext sslContext ) { } public HostnameVerifier getHostNameVerifier ( ) { } public void setHostNameVerifier ( HostnameVerifier hostNameVerifier ) { } public Integer getSlowTime ( ) { } public void setSlowTime ( Integer slowTime ) { } public Map < String , String > getCommonHeaders ( ) { } public void setCommonHeaders ( Map < String , String > commonHeaders ) { } public Proxy getConnectionProxy ( ) { } public void setConnectionProxy ( Proxy connectionProxy ) { } public static SimpleHttpClient getThis ( ) { } }

Fix:
return SimpleHttpClient . post ( url , headers , params , charset , null ) ;